Coughing is a protective reflex action that expels foreign bodies or secretions from the respiratory tract and is beneficial to the body. However, coughing also has a negative side. For example, coughing can increase the intrathoracic pressure and increase the burden on the heart, and violent coughing can lead to respiratory bleeding, spontaneous pneumothorax, and even induce syncope and lead to rib fractures. Therefore, frequent and violent coughing can do more harm than good if it interferes with work and rest. As a common symptom of respiratory diseases, the cough reflex can be caused when organs such as the ears, nose, throat, larynx, bronchi, pleura and lungs are irritated by inflammation, stasis of blood, physical, chemical or allergic factors. There are many different diseases that can cause a cough, and it is not like what most people think: “A cough is a cold, a simple cough does not need to be taken seriously, it may be pharyngitis or bronchitis, no need for a specialist visit, just prescribe some anti-inflammatory or cold medicine.” A number of patients go to medical institutions with this mentality and are prescribed medication. Due to the complex etiology of chronic cough, clinically, 70% of patients with chronic cough are misdiagnosed and most patients are misdiagnosed with “chronic bronchitis” or “bronchiectasis” when in fact it is due to other causes. The frequent use of repeated antibiotic treatments or meaningless tests also results in a huge waste of medical resources. Chronic cough has become a difficult problem for many doctors and patients. Many patients have the disease for several years, which seriously affects their daily life and work. Therefore, it is very important for medical institutions to increase the importance of chronic cough and to master the differential diagnosis and treatment of chronic cough. In medicine, the previous definition of chronic cough was that a cough lasting more than 3 weeks was considered chronic. The current definition is that a cough lasting more than 8 weeks with no obvious lesions on chest x-ray is considered chronic. For these patients, do not simply assume that it is caused by bronchitis. There are two main categories of chronic cough that are usually common: one is a general chest X-ray with no obvious abnormalities and cough as the main or only symptom. There are four common types: 1) cough due to postnasal drip syndrome; 2) cough due to cough variant asthma; 3) gastroesophageal reflux cough; and 4) cough due to eosinophilic bronchitis. The other category is those with clear lesions on initial X-ray chest radiographs, such as pneumonia, tuberculosis, interstitial lung fibrosis, bronchopulmonary cancer, etc. It is also important for physicians to note that some medications can also cause cough, such as commonly used antihypertensive drugs, angiotensin-converting enzyme inhibitors (Kepone), cardiovascular medications (Amiodarone), and certain diuretics. In addition to the common causes of cough, there are many other less common causes of cough, and in some cases, cough symptoms caused by other systemic pathologies should be considered.